Download Experimental study of Aerodynamics over a flat plate.

Experimental study of Aerodynamics over a flat plate.
Instructor: Igal Gluzman Department of Aerospace Eng.
Abstract
The term “aerodynamics” is generally used for problems arising from flight and other topics
involving the flow of air [1].
In our world the aerodynamics phenomena can be found anywhere. For example: we use
airplanes and cars which all affected by the air flow. The air flow can generate lift under
airplane wings which make it possible to fly, the same air flow can generate drag force over
a solid body, such as a hand that reached out of a window of fast moving car, will
experience resistance of air flow.
The flow over a plate behaves differently at different locations along the plate: changing
from laminar to turbulent corresponding to different values of Reynolds number. The fluid
flow over any solid surface can be divided in to two areas by boundary layer, which differs
between the properties of the flow behavior close to surface (inside boundary layer), and
away from the surface (outside the boundary layer), as demonstrated in Figure 1. The flow
close to surface is affected by the surface due to viscosity and creates the majority drag
force. However the flow outside the boundary layer is less altered by the surface.
In this study air flow over flat plate will be studied experimentally inside a wind tunnel.
Laminar and turbulent velocity profiles will be acquired experimentally by using hot-wire
anemometer device (see Figure 2), and compered with theoretical and numerical results
(the similarity solution of Blasius for laminar flow).
Lami
Turbul
Figure.1- Flow velocity profile inside and outside the boundary layer over a
flat plate [2].
1
Figure.2- Schematic of a hot-wire probe [3].
References:
[1] Anderson Jr, John David. Fundamentals of aerodynamics, Tata McGraw-Hill Education,
1985.
[2] http://aerojockey.com/papers/bl/node1.html
[3] R. Figliola, D. Beasley, Theory and Design for Mechanical Measurements, 5th ed - Wiley,
2011.
Student mission / Objective:
1. Introduction to boundary layer theory.
2. Experimental measuring of laminar and turbulent boundary layers over a flat plate inside
wind tunnel.
3. The experimental results will be compared with theoretical and numerical predictions.
The student will be introduced to:
Wind tunnel operation, using advanced laboratory measuring equipment such as: Pitot
tube, hot wire anemometer, Scope, and introduction to computer software: LabView and
Matlab.
Requirements:
Please watch the following video:
https://www.youtube.com/watch?v=nzgqRb2KstM
Boundary Layers video from the 1960's video lecture series on fluid mechanics.
Please read the following:
2
1. Pitot Tube: http://en.wikipedia.org/wiki/Pitot_tube
2. Hot wire anemometer: http://www-g.eng.cam.ac.uk/whittle/currentresearch/hph/hot-wire/hot-wire.html
Questions:
1. From the video, can you tell what the difference between laminar and turbulent flow?
2. Describe the working principles of Pitot tube and Hot wire anemometer.
We will discuss the answers when we meet at the dinner in the opening ceremony.
Recommended reading material:
Please read the following paper in order to get a sense of the project
Blasius boundary layer:
http://en.wikipedia.org/wiki/Blasius_boundary_layer
Similarity solution:
http://en.wikipedia.org/wiki/Similarity_solution
Please fill free to contact me with questions regarding the project at:
[email protected]
3